Phase-mixing of Langmuir oscillations in cold electron-positron-ion plasmas

Plasma-based accelerators sustain accelerating gradients which are several orders greater than obtained in conventional accelerators. Focusing of electron and positron beams by wakefield, excited in plasma, in electron-positron collider is very important. The focusing mechanism in the plasma, in which all electron bunches of a sequence are focused identically, has been proposed by authors earlier. The mechanism of focusing of a sequence of relativistic positron bunches in plasma, in which all positron bunches of sequence are focused identically and uniformly, has been investigated in this paper by numerical simulation by 2.5D code LCODE. Mechanism of this identical and uniform focusing involves the use of wave-length λ, which coinciding with double longitudinal dimension of bunches λ=2Db, the first bunch current is in two times smaller than the current of the following bunches of sequence and the distance between bunches equals to one and a half of wavelength 1.5λ. We numerically simulate the self-consistent radial dynamics of lengthy positron bunches in homogeneous plasma. In simulation we use the hydrodynamic description of plasma. In other words the plasma is considered to be cold electron liquid, and positron bunches are aggregate of macroparticles. Positron bunches are considered to be homogeneous cylinders in the longitudinal direction. Positrons in bunches are distributed in radial direction according to Gaussian distribution. It is shown that in this case only first bunch is in the finite longitudinal electrical wakefield Ez¹0. Other bunches are in zero longitudinal electrical wakefield Ez=0. Between bunches of this sequence longitudinal electrical wakefield and radial force are not zero Ez¹0, Fr¹0. The focusing radial force in regions, occupied by bunches, is constant along each bunch Fr=const. Between bunches the radial force is inhomogeneous Fr¹const. All positron bunches of sequence are focused identically and uniformly.

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Langmuir wave phase-mixing in warm electron-positron-dusty plasmas

Physics Letters A ◽

10.1016/j.physleta.2018.02.020 ◽

2018 ◽

Vol 382 (15) ◽

pp. 1020-1023 ◽

Cited By ~ 7

Author(s):

Sourav Pramanik ◽

Chandan Maity

Keyword(s):

Langmuir Wave ◽

Dusty Plasmas ◽

Phase Mixing ◽

Wave Phase ◽

Electron Positron

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Phase-mixing of electrostatic modes in a cold magnetized electron-positron plasma

Physics of Plasmas ◽

10.1063/1.4817749 ◽

2013 ◽

Vol 20 (8) ◽

pp. 082302 ◽

Cited By ~ 8

Author(s):

Chandan Maity ◽

Nikhil Chakrabarti ◽

Sudip Sengupta

Keyword(s):

Phase Mixing ◽

Electron Positron

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Breaking of a Langmuir wave in cold electron–positron–ion plasmas

Plasma Science and Technology ◽

10.1088/2058-6272/aa8cc0 ◽

2017 ◽

Vol 20 (1) ◽

pp. 014008 ◽

Cited By ~ 4

Author(s):

Suyun ZHOU ◽

Hui CHEN ◽

Yanfang LI

Keyword(s):

Langmuir Wave ◽

Cold Electron ◽

Electron Positron

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Ion-acoustic double layers in electron–positron–ion plasmas with finite ion temperature

Journal of Plasma Physics ◽

10.1017/s0022377813000159 ◽

2013 ◽

Vol 79 (5) ◽

pp. 661-675 ◽

Cited By ~ 13

Author(s):

S. K. JAIN ◽

M. K. MISHRA

Keyword(s):

Double Layer ◽

Small Amplitude ◽

Double Layers ◽

Cold Electron ◽

Ion Temperature ◽

Temperature Ratio ◽

Plasma Parameters ◽

Electron Positron ◽

Ion Acoustic ◽

Ion Acoustic Double Layers

AbstractThe large-amplitude ion-acoustic double layers in a collisionless plasma consisting of isothermal positrons, warm adiabatic ions and two-temperature distribution of electrons are investigated. Using the pseudo-potential approach, an energy-integral equation for the system has been derived which encompasses complete nonlinearity for the plasma system. The existence region of the double layers is analyzed numerically. It is found that for a selected set of physical parameters, the rarefactive double layer exists in the electron–positron–ion plasma. It is found that the existence regime of the double layer is very sensitive to the plasma parameters, e.g. cold electron concentration (μ) and temperature ratio of two electron species (β). An increase in the finite ion temperature ratio increases the amplitude of the rarefactive double layer. To study small-amplitude double layers, we have expanded the Sagdeev potential. In the case of small amplitude, it is found that the amplitude of the double layer increases with increase in ion temperature ratio (σ) and cold electron concentration (μ). However increase in positron concentration (α) and temperature ratio of positrons to electrons (γ) decreases the amplitude of the double layer. The effect of various plasma parameters on the characteristics of the double layers is discussed in detail. The results of the investigation may be helpful to understanding basic plasma characteristics in space.

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